Stabilizing color binding agent



Patented Mar. r, 1939 essence a cocoa mmome sonny Fetch Harm von und zu Guttenberg, Gent and Budolt Kdhler, Dusseldorf-hen m Dusseldorll, Germany .12! assignors to the Henlsel a hart mlt heschrlinlrter Haitians,

No lllra. our application time 15,1935, den-tel No. cases. Divided and this application -otoher 25, 193?. enial No. 170,955. in Germany done so, rose This invention relates to a color binding agent and more particularly to a stabilized color binding agent and to a method oi stabilizing the some.

Color binding agents embodying a colloidal dispersion oi an oily substance in an aqueous medium are almost always unstable structures.

agent. .We have now succeeded in finding an addition which stabilizes such color binding agents that are of the greatest interest for practice, and

20) which at least represses the ageing phenomena.

According to the invention, polyphosphates are incorporated with such color binding agents.

Preferably, water-soluble polyphosphates, par-=- ticularly alkali polyphosphates, come into consid- 25 eration. The latter may be produced by melting alkali pyrophosphates with alkali metaphosphates, or directly from their starting substances.

For example, sodium polyphosphates oi the rior= mulae NatPaOio. NacPsOie, NanPcOzs, and

w NamPioOai may be employed.

The use of polyphosphates for stabilizing such color binding agents'ls extremely varied. Color binding agents may be stabilized in which there is an extremely fine dispersion (limit region oi 5 molecular solubility) or coarser colloidal dispersion up to the limit of coarse mechanical dispersions. By the addition of polyphosphates, ageing phenomena, such as for instance flocculation,

thickening of sols, gelatlnisation or, in the case or jellies, syneresis, may be prevented. More particularly, concentrated colloidal dispersions,

, I which are very subject to the said phenomena,

may be stabilized by an addition of polyphoscs phates. I

The choice of the polyphosphate depends inter alia upon the pI-l-value' which is brought about by the polyphosphate. Preferably, polyphos-v phates are selected, the pH-value of which agrees with thedesired optimum pH-value oi the colloid.

The following are the pi-l values or the polyphos= pirates: v phi NasPsOm d9 NacPrOr- 8.3 NaicPmOm 3.1

The quantities of polypho'sphate employed depend upon the nature of the colloidal dispersion which is to be stabilized. Frequently, the addition may be less than 1% or even less than 0.1%. The addition of polyphosphates is preferably made to technical color binding agents which are ill only employed some time after their manufac= ture. If desired, the polyphosphates may also be added to colloidal dispersions which are made or which form only immediately upon use. The polyphosphates exhibit a stabilizing efiect both in the cold'and when hot.

The polyphosphates may also he employed in the presence of other known stabilizing agents, such as for example decomposition products of albumen, such as lysalbinlc acid. Furthermore, the soluble salts of other phosphoric acids which contain less water than o'rthophosphorlc acid, for-example alkali pyrophosphates or hypophosphates may be combined with the polyphosphates. The polyphosphates are eminently suitable for stabilizing such color binding agents. Thus, for

' example, emulsions of oils in aqueous caseinate solutions are often employed for paint purposes.

These emulsions may be stabilized by the addition.

or polyphosph'ates, so that even after the addition of the colour pigment, no subsequent thickening occurs, and the finished mixtures retain their good spreading properties,

' Example A color binding agent is made by emulsifying 400 grams of linseed oil in 600 grams of a. solution of 80 grams of casein in 500 grams of water and 20 grams of concentrated ammonia, with the polyphosphates, subsequent thickening occurs, so that even after some time the paint becomes so stifl that it can only be spread with difficulty.

We claim.

1. The method of stabilizing a color binding agent embodying a colloidal dispersion of a drying oil in an aqueous solution of an alkaline caseinate which comprises incorporating water-soluble polyphosphates therewith selected from the group consisting of NaaPaOm; NESPAOU; NanPoOzl and NamPmOai.

2. As a new article of manufacture, a color binding agent comprising a colloidal dispersion of adrying oil in an aqueous solution of an alkaline caseinate and stabilized by containing a. predetermined quantity of a water-soluble polyphosphate selected from the group consisting oi. NaaPaoioi NacPioia; NanPnOu and N812Pi003i.

v FRIEDRICH HOERMANN von UND zu GUTIENBERG.

annou- KCSHLER. 

